José Mourinho is ready to step up his pursuit of Wayne Rooney next week and claims Manchester United should have no qualms about selling the striker to a domestic rival, saying it could damage the Premier League if he is not allowed to move. Chelsea have already made two bids for the forward but will wait until after the sides play at Old Trafford on Monday before making a third approach.

Rooney, who could be named in the starting XI by David Moyes against Chelsea, has been a long-term target of Mourinho, with the Portuguese claiming one more addition at Stamford Bridge before the transfer window closes would be the "final piece" in his jigsaw and that the club's interest in the player is not simply a tactic to unsettle their rivals.

Mourinho believes that if United sell Rooney to a foreign club they would be damaging the league, claiming players moving between rivals should not be a major issue. "That old-fashioned mentality of 'I don't sell players to the same country' doesn't help the market and doesn't help the players," he said. "You see in Italy, it happens every season without any problem. The player wants to move from Milan to Inter, from Inter to Milan, from Roma to Juventus, from Juventus to Inter, and they do this all the time. You see [Filippo] Inzaghi, he played for Juventus, for Milan, for Inter. From the big ones I think only [Francesco] Totti stayed all his life. [Andrea] Pirlo – Inter, Milan, Juventus.

"Sometimes you push players abroad when you should be interested in keeping them in your league, because when you keep players in your league you are contributing to make your league the best league. So when you want to sell and you are pushing the players abroad I think you are giving the wrong contribution to the league where you are."

Chelsea have already added André Schürrle and Marco van Ginkel to their midfield ranks during the transfer window and are expected to confirm the arrival of Brazilian Willian after luring the attacker to Stamford Bridge when he was on the brink of agreeing a deal with Tottenham.

United are adamant that Rooney will not be sold this summer to any club, domestic or foreign. However, Mourinho is determined to step up his interest next week and insisted his tactics in the transfer window are not merely intended to unsettle the player.

"I don't understand that [argument] because it's normal that we want to strengthen our squad in every position," he said. "We did it from the goalkeeper, we did it in midfield, we did it in creative positions – we didn't in the striker's position where we have kept the players we had last year.

"I think it is basic and normal that we want to give more quality to the whole structure. It is obvious that the striker's position was a position where we would try to improve."

Mourinho, who spent two years in Italy with Internazionale, remains hopeful of securing Rooney's signature but reiterated that he has a "plan B and plan C" in place should his pursuit of the 27‑year‑old fall through. The former Real Madrid manager also denied that Juan Mata would be allowed to leave in exchange for Rooney and claimed that United had never enquired about the Spanish playmaker.

"We are going to get a maximum of two players in this transfer window," added Mourinho "If we get the second piece, it will be the final piece. Let's see, [if] we make the bid and they say no again, what do we lose? One email.

"The two answers we got from Manchester United were 'we don't accept the bid, we are not interested in selling the player'. That's the only official contact we have had. It is the same till Monday, we have nothing else we would like to add to it and we want to respect them and football."